Conventionally, fully automatic transmissions having no clutch pedal have been developed in vehicles such as heavy-duty trucks. According to a vehicle having such a fully automatic transmission, it is possible to automatically start the vehicle such as a heavy duty truck only by depressing the accelerator pedal, but since a starting condition is largely varied, it is difficult to sufficiently satisfy the requirement of the starting performance from a driver only by automatic start control. That is, in the vehicle such as heavy-duty truck, since the weight of carrying load is largely varied, the starting condition of the vehicle largely changes in some cases. The starting condition of the vehicle also largely changes depending upon the road conditions such as whether a road on which the vehicle starts is a slope, a mud road, bumpy road and the like. Therefore, it is very difficult to reliably control the automatic start of the vehicle in accordance with all kinds of variations of the starting condition of the vehicle.
To solve this problem, there has been proposed an invention concerning a start control apparatus of a vehicle having an automatic start function of a vehicle by determining a starting condition of the vehicle. For example, as described in Japanese Unexamined Patent Publication No. 2002-286054, a conventional start control apparatus of a vehicle of this kind is provided with a clutch pedal capable of manually starting the vehicle, a clutch pedal sensor for detecting the depression of the clutch pedal, automatic start control means for automatically starting the vehicle, automatic start interrupting means which interrupts the control of the automatic start by the automatic start control means when only the depression of the clutch pedal is detected by the clutch pedal sensor and which switches the starting mode to the manual starting mode. In such a start control apparatus of the vehicle, the above-mentioned automatic start interrupting means is configured so that the control of the automatic start of the vehicle is interrupted only by the depressing operation of the clutch pedal, and the starting mode is switched to the manual start.
Further, the conventional start control apparatus of the vehicle has been provided with an alarming means which gives an alarm when the above-mentioned automatic start interrupting means is operated. If a driver depressed the clutch pedal to switch the automatic start mode to the manual starting mode, the depression of the clutch pedal is detected by the clutch pedal sensor, and the alarming means produces an alarm sound. With this, it is possible to avoid a condition such that the operation of the engine is unintentionally stopped due to a careless release of a foot from the clutch pedal by a driver.
In such a conventional start control apparatus of the vehicle, however, when the driver depresses the clutch pedal during control of the automatic start of the vehicle by mistake, although it is possible to avoid, by the production of the alarm sound, the unintentional stopping of the operation of the engine due to the driver's careless release of the foot from the clutch pedal, if the driver desires to return the starting mode to the automatic start after the starting mode is switched to the manual starting mode by the depressing operation of the clutch pedal, the driver must carry out a predetermined operation to reset the control of the automatic start. Thus, the operability of the automatic start of the vehicle is poor.
Hence, it is an object of the present invention to provide an automatic start control apparatus of a vehicle, which is capable of solving the above problem, and enhancing the operability of the automatic start of the vehicle through such an operation that the starting mode is not switched only by the depressing operation of the clutch pedal, and the starting mode is switched to the manual starting mode when the accelerator pedal, together with the clutch pedal, is operated.